Today around 12:40 UTC I have scanned the bench in TY and in X with the OMC shutter open, to see if the beam transmission is much higher on the right side of the B1s camera where there is a bright spot on B1s in LN2 (Figure 1). This could be the case if for example that part of the beam was passing next to the coating. I haven't seen any brightening when trying to put the MICH flashes beam through that spot. Actually that is the place where the beam starts to be clipped and stops reaching the camera. So it is unlikely that the bright spot vislbe on the right edge of the B1s beam is due to a higher transmission of light through the B1s beam splitter at that location.